The CyanogenMod team has issued all the new CM 13 Nightlies for all the Galaxy S5 DUOS China models. You can learn how to flash such custom ROM on your device by checking all the info listed in this post.

CM 13 Nightly builds are based on the AOSP Android 6.0 releases, which means that you will get all the stock Lollipop functions along with all the CyanogenMod goodies. Check more about this release at CyanogenMod's blog page here.

Note that the CM 13 Lollipop Nightly builds are not Final releases, and that you might find some errors and bugs while testing them. Make sure that you will continue to update the installed CM 13 Nightlies on a regular scheduler.

Read the following guidelines before starting the installation process of CM 13:

use the tutorial only for the Samsung Galaxy S5 DUOS models sold in China.
- the model numbers supported by this guide are the following ones: SM-G9006W, SM-G9008W.
- don't attempt to use this post for any other different devices.

your smartphone has to be rooted.
- also, a custom Recovery that's based on CWM or TWRP versions should do the trick.
- the installed custom Recovery has to be updated to its latest version, so that it will support all the Android 6.0 custom ROMs.

you should use this post only if you're an advanced user.
- we won't be held responsible in case you end up bricking your device nor in case you lose any data in the process.

in the tutorial part of this post you can find two extra preparation steps: the NANDROID ROM Backup and the Factory Reset ones.
- the NANDROID Backup creates a full restore point for your device, one that you can prove to be very useful in case your device doesn't boot in normal mode.
- the 'factory reset' process wipes clean the system memory partition, but it won't delete any data from internal storage.
- factory resetting the device removes the old custom ROM and it allows the CM 13 Nightly build to boot in normal mode.

Find the CM 13 zip and confirm its installation.
- don't press any buttons until all files are done installing.

When the CM 13 is installed you can flash the Gapps zip, too.

Reboot your phone in normal mode after all files are flashed.

Use your default login info in order to regain control over your device once again.

Also, make sure to add the same Google account on your device as you did before, it will enable you to regain control over your device once again.

Note that the first boot process of this new custom ROM will take a while before it completes.

If installation fails and the phone gets stuck at the boot animation screen, or it enters in a boot loop, then you will be forced to repeat the installation. If you repeat the CM 13 installation, then you have to make sure that your device meets all requirements and that you won't be skipping any steps listed above. Feel free to ask for more help by using the comments field below.